I'm hosting an internet site where i host my primary site within the /home/username/public_html as i host my blog in /home/username/blog

could it be safe which i host your blog inside a different folder (/home/username/blog )

There's nothing special in regards to a directory known as "public_html" apart from that the net server are frequently set up to search for content there (plus some web servers achieve this automatically).

The title is simply a convention.